#define _CRT_SECURE_NO_WARNINGS 1

#include<stdio.h>
int main()
{
	int n1 = 0;
	int n2 = 0;
	int n3 = 0;
	int n4 = 0;
	scanf("%d %d %d %d", &n1, &n2, &n3, &n4);
	int max = n1;
	if (n2 > max)
		max = n2;
	if (n3 > max)
		max = n3;
	if (n4 > max)
		max = n4;
	printf("%d\n", max);

	return 0;
}